1. Field of the Invention
The present invention relates to an ultrasonic diagnosis apparatus, and more particularly, to a method of effectively controlling an acoustic output of the ultrasonic diagnosis apparatus by setting an individual output in a combinational mode that may provide at least two pulser output signals in accordance with safety standards, such as a mechanical index (MI), a thermal index (TI), and the like, which may be determined by international regulatory standards, for example National Electrical Manufacturers Association (NEMA), International Electrotechnical Commission (IEC), Food and Drug Administration (FDA), and the like.
2. Description of the Related Art
An ultrasonic diagnosis apparatus is an apparatus for transmitting, from the surface of a body of an object, an ultrasonic wave signal toward a predetermined structure inside the body, and for obtaining an image with respect to a cross section of soft tissues or a blood flow using information of the ultrasonic wave signal reflected from the tissues of the body.
This ultrasonic diagnosis apparatus has advantages of a small size, a low cost, a real-time display, and a high stability without exposing patients and users to X-ray radiation and the like, and thus, the ultrasonic diagnosis apparatus is widely used along with other diagnostic imaging systems such as an X-ray diagnosis equipment, a computerized tomography (CT) scanner, a magnetic resonance imaging (MRI) equipment, a nuclear medicine diagnosis equipment, and the like.
Generally, an acoustic output of an ultrasonic diagnosis apparatus is limited and determined by international standards, for example, a mechanical index (MI). Here, the MI corresponds to an index that may quantize effects of mechanical factors, which an ultrasonic wave may have, on a human body. As another example of the international standards, there also exists a thermal index (TI). As is commonly known, the international permissible standards for the MI and the TI may correspond to an MI of less than 1.9 and a TI of less than 6.0.
The ultrasonic diagnosis apparatus may diagnose an object more precisely by increasing a transmission voltage of a pulser and consequently an acoustic output. When the transmission voltage is increased, quality of an image may become higher. However, a problem may occur in that values of items of the safety standards such as the MI, the TI, and the like may proportionally increase.
The high values of the items may indicate that the ultrasonic diagnosis apparatus may have a greater effect on the human body, and accordingly the use of the corresponding ultrasonic diagnosis apparatus may be limited by the international standards when the values are greater than a predetermined level.
The ultrasonic diagnosis apparatus may operate in several modes, such as a brightness (B) mode, a power Doppler (pD) mode, and the like, and may also operate in combinational modes, such as a B+pD mode or a B+pD+CD mode according to a choice of a user. The CD mode may refer to a color Doppler mode.
In the combinational modes, pulses having at least two levels of voltage outputs may be outputted, and the outputted voltage may be needed to be controlled so that an individual voltage output may be within international regulatory standards.